title: Comparison of the induction of immunoglobulin M and G antibodies in mice with purified pneumococcal type 3 and meningococcal group C polysaccharides and their protein conjugates.
abstract: The nature and kinetics of the serum antibody response to pneumococcal type 3 and meningococcal group C polysaccharides and their protein conjugates were studied in mice. Bovine serum albumin and diphtheria and tetanus toxoids were used as carrier proteins. The purified polysaccharides induced only immunoglobulin M (IgM) antibodies in thymus-bearing as well as congenic athymic (nude) mice. The polysaccharides covalently conjugated to proteins produced IgM and IgG antibodies in normal mice, but only IgM antibodies in nude mice. A second dose of the polysaccharide-protein conjugates resulted in a booster effect in the IgG response to the polysaccharides. Moreover, memory B-cells, generated after a primary injection with the polysaccharide-protein conjugates, could be triggered to the production of IgG antibodies after a second injection with the pure polysaccharides alone. These data indicate that the antibody response to the pure polysaccharides is thymus independent and that this response can be changed into a thymus-dependent response by covalent conjugation of the polysaccharide to a thymus-dependent protein.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000276:immunology; D004168:Diphtheria Toxoid; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D051379:Mice; D008819:Mice, Nude; D009345:Neisseria meningitidis / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012710:Serum Albumin, Bovine; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D013745:Tetanus Toxoid
chemical_list: D000907:Antibodies, Bacterial; D004168:Diphtheria Toxoid; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D012710:Serum Albumin, Bovine